TAFR: A TTL-aware Message Ferry Scheme in DTN

Partitioning network, especially some DTN, can use Message Ferry(MF) scheme to restore network connection. Message TTL describes the maximum delay tolerance of transmission and messages with out-of-date TTL should be dropped. In this paper, we will study the problem of how to design the ferry's moving route dynamically to get high message delivery ratio under the constraint of message TTL, which we call it TAFR problem as well as algorithms. We compare TAFRA to existing SIRA and Random Way point algorithm with different message TTLs and ferry number in two scenarios. The simulation shows that TAFRA can get nearly twice the delivery ratio than SIRA in low message TTL conditions, and 50% more delivery ratio with increasing ferry number. Furthermore, the simulation shows that TAFRA provides on-demand characteristics which are more suitable in some non-uniformly distribute message condition.